Wireless communications systems are used in a variety of telecommunications systems, television, radio and other media systems, data communication networks, and other systems to convey information between remote points using wireless transmitters and wireless receivers. A transmitter is an electronic device which, usually with the aid of an antenna, propagates an electromagnetic signal such as radio, television, or other telecommunications. Transmitters often include signal amplifiers which receive a radio-frequency or other signal, amplify the signal by a predetermined gain, and communicate the amplified signal. On the other hand, a receiver is an electronic device which, also usually with the aid of an antenna, receives and processes a wireless electromagnetic signal. In certain instances, a transmitter and receiver may be combined into a single device called a transceiver.
Transmitters, receivers, and transceivers often include components known as oscillators. An oscillator may serve many functions in a transmitter, receiver, and/or transceiver, including generating a local oscillator signal (usually in a radio-frequency range) for upconverting baseband signals onto a radio-frequency (RF) carrier and performing modulation for transmission of signals, and/or for downconverting RF signals to baseband signals and performing demodulation of received signals.
In many instances, oscillators may include a crystal resonator and may be tuned to a specific frequency. However, specific functions in wireless communication devices may require a modified oscillator signal. For example, an upconverter or a downconverter may require an oscillator signal at a lower frequency than provided by the crystal resonator. Similarly, and upconverter or a downconverter may require an oscillator signal with a modified duty cycle. Digital circuitry may accompany an oscillator in order to provide such a modified signal. However, any additional circuitry used to modify the oscillator signal will result in undesired power consumption when in use.